Remplace AES encryption with database. For saving PKCE parameters.

oidc_provider/lib/endpoints/token.py

@@ -1,4 +1,4 @@
-from base64 import b64decode, urlsafe_b64encode
+from base64 import b64decode, urlsafe_b64decode, urlsafe_b64encode
 import hashlib
 import logging
 import re
@@ -73,10 +73,11 @@ class TokenEndpoint(object):
             logger.debug('[Token] Client does not exist: %s', self.params.client_id)
             raise TokenError('invalid_client')
 
-        if not (self.client.client_secret == self.params.client_secret):
-            logger.debug('[Token] Invalid client secret: client %s do not have secret %s',
-                         self.client.client_id, self.client.client_secret)
-            raise TokenError('invalid_client')
+        if self.client.client_type == 'confidential':
+            if not (self.client.client_secret == self.params.client_secret):
+                logger.debug('[Token] Invalid client secret: client %s do not have secret %s',
+                             self.client.client_id, self.client.client_secret)
+                raise TokenError('invalid_client')
 
         if self.params.grant_type == 'authorization_code':
             if not (self.params.redirect_uri in self.client.redirect_uris):
@@ -97,16 +98,13 @@ class TokenEndpoint(object):
 
             # Validate PKCE parameters.
             if self.params.code_verifier:
-                obj = AES.new(hashlib.md5(django_settings.SECRET_KEY).hexdigest(), AES.MODE_CBC)
-                code_challenge, code_challenge_method = tuple(obj.decrypt(self.code.code.decode('hex')).split(':'))
-
-                if code_challenge_method == 'S256':
+                if self.code.code_challenge_method == 'S256':
                     new_code_challenge = urlsafe_b64encode(hashlib.sha256(self.params.code_verifier.encode('ascii')).digest()).replace('=', '')
                 else:
                     new_code_challenge = self.params.code_verifier
 
                 # TODO: We should explain the error.
-                if not (new_code_challenge == code_challenge):
+                if not (new_code_challenge == self.code.code_challenge):
                     raise TokenError('invalid_grant')
 
         elif self.params.grant_type == 'refresh_token':

oidc_provider/lib/utils/token.py

@@ -1,10 +1,9 @@
+from base64 import urlsafe_b64decode, urlsafe_b64encode
 from datetime import timedelta
 import time
 import uuid
 
-from Crypto.Cipher import AES
 from Crypto.PublicKey.RSA import importKey
-from django.conf import settings as django_settings
 from django.utils import timezone
 from hashlib import md5
 from jwkest.jwk import RSAKey as jwk_RSAKey
@@ -108,16 +107,11 @@ def create_code(user, client, scope, nonce, is_authentication,
     code.user = user
     code.client = client
 
-    if not code_challenge:
-        code.code = uuid.uuid4().hex
-    else:
-        obj = AES.new(md5(django_settings.SECRET_KEY).hexdigest(), AES.MODE_CBC)
-
-        # Default is 'plain' method.
-        code_challenge_method = 'plain' if not code_challenge_method else code_challenge_method
-
-        ciphertext = obj.encrypt(code_challenge + ':' + code_challenge_method)
-        code.code = ciphertext.encode('hex')
+    code.code = uuid.uuid4().hex
+    
+    if code_challenge and code_challenge_method:
+        code.code_challenge = code_challenge
+        code.code_challenge_method = code_challenge_method
 
     code.expires_at = timezone.now() + timedelta(
         seconds=settings.get('OIDC_CODE_EXPIRE'))

oidc_provider/migrations/0013_auto_20160407_1912.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9 on 2016-04-07 19:12
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('oidc_provider', '0012_auto_20160405_2041'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='code',
+            name='code_challenge',
+            field=models.CharField(max_length=255, null=True),
+        ),
+        migrations.AddField(
+            model_name='code',
+            name='code_challenge_method',
+            field=models.CharField(max_length=255, null=True),
+        ),
+    ]

oidc_provider/models.py

@@ -86,6 +86,8 @@ class Code(BaseCodeTokenModel):
     code = models.CharField(max_length=255, unique=True)
     nonce = models.CharField(max_length=255, blank=True, default='')
     is_authentication = models.BooleanField(default=False)
+    code_challenge = models.CharField(max_length=255, null=True)
+    code_challenge_method = models.CharField(max_length=255, null=True)
 
     class Meta:
         verbose_name = _(u'Authorization Code')

oidc_provider/tests/app/utils.py

@@ -13,7 +13,8 @@ from oidc_provider.models import *
 
 FAKE_NONCE = 'cb584e44c43ed6bd0bc2d9c7e242837d'
 FAKE_RANDOM_STRING = ''.join(random.choice(string.ascii_uppercase + string.digits) for _ in range(32))
-FAKE_CODE_CHALLENGE = 'pG6flQqJa7INfIKb5cZVAXhTqvTKehIck6aQhdUuyWc'
+FAKE_CODE_CHALLENGE = 'YlYXEqXuRm-Xgi2BOUiK50JW1KsGTX6F1TDnZSC8VTg'
+FAKE_CODE_VERIFIER = 'SmxGa0XueyNh5bDgTcSrqzAh2_FmXEqU8kDT6CuXicw'
 
 
 def create_fake_user():

oidc_provider/tests/test_token_endpoint.py

@@ -445,3 +445,23 @@ class TokenTestCase(TestCase):
 
         self.assertEqual(id_token.get('test_idtoken_processing_hook2'), FAKE_RANDOM_STRING)
         self.assertEqual(id_token.get('test_idtoken_processing_hook_user_email2'), self.user.email)
+
+    def test_pkce_parameters(self):
+        """
+        Test Proof Key for Code Exchange by OAuth Public Clients.
+        https://tools.ietf.org/html/rfc7636
+        """
+        import pdb;pdb.set_trace()
+        code = create_code(user=self.user, client=self.client,
+                           scope=['openid', 'email'], nonce=FAKE_NONCE, is_authentication=True,
+                           code_challenge=FAKE_CODE_CHALLENGE, code_challenge_method='S256')
+        code.save()
+
+        post_data = self._auth_code_post_data(code=code.code)
+
+        # Add parameters.
+        post_data['code_verifier'] = FAKE_CODE_VERIFIER
+
+        response = self._post_request(post_data)
+
+        response_dic = json.loads(response.content.decode('utf-8'))